<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style>
*{margin:0;padding:0}
body{background:#c7edcc;}
input{width:100px;height:30px;}
</style>

</head>

<body>
	<input type="button" id="myBtn"/>
    <script>
    	var btn=document.getElementById('myBtn');
				
		var aa=function(){
			console.log('hello world');	
		}
		
		var EventUtil={
				//绑定事件
				addHandler:function(element, type, handler){
					if(element.addEventListener){
						element.addEventListener(type, handler, false);
					}else if(element.attachEvent){
						element.attachEvent('on'+type, handler);	
					}else{
						element['on'+type]=handler;
					};
				},
				
				//删除事件
				removeHandler:function(element, type, handler){
					if(element.removeEventListener){
						element.removeEventListener(type, handler, false);
					}else if(element.detachEvent){
						element.detachEvent('on'+type, handler);	
					}else{
						element['on'+type]=null;
					};
				}	
		};
		
		EventUtil.addHandler(btn, 'click', aa);
		
		EventUtil.removeHandler(btn, 'click', aa);
    </script>
</body>
</html>
